The present invention relates to a method of arranging interactive service, a program of arranging interactive service, a recording medium for storing the program and a service broker.
A system in which a certain computer entrusts (arranges) a predetermined process to another computer is known widely. For example, according to JP-A-2004-38972, in a plurality of servers (described as “work stations” in JP-A-2004-38972) connected to one another by a network, a process unit (described as “grid calculation work load” in JP-A-2004-38972) is arranged on the basis of internal information of the servers such as frequencies in use.
According to JP-A-2004-38972, processing is performed in such a manner that a broker (described as “grid” in JP-A-2004-38972) selects a server allowed to execute the process unit on the basis of the processing capacity necessary for execution of the process unit and arranges the process unit in the selected server.
In the background art described in JP-A-2004-38972, when a process unit mainly including a numerical calculation process such as an arithmetic process is provided as a subject, the process unit can be executed by only processing in the inside of a server. Accordingly, the broker entrusting a process can allocate an appropriate server on the basis of information concerning the internal state of each server.
Incidentally, a service providing process is carried out between a server providing a service and a client receiving the service. Interactive service is the form of provision of service in which request messages and reply messages concerning service are transmitted and received frequently (several times) between a server and a client.
On the other hand, batch processing service is the form of provision of service in which the client's entrusting of service to a server is performed once collectively and in which the server's provision of service to a client is performed once collectively. The batch processing service is distinguished from the interactive service.
Accordingly, the interactive service is different from the batch processing service in that data concerning service are exchanged frequently between a server and a client. In the interactive service, the client's environment such as the quality of communication between the server and the client has a large influence on the provision quality of service.
Accordingly, when a process unit is used not for mainly performing numerical calculation but for providing interactive service (e.g. information retrieval service) to an end user, a problem occurs. That is, the background art has a problem that a server for providing service of an appropriate quality to an end user cannot be selected because there is no consideration for the end user using the interactive service when a server in which a process unit is arranged for providing interactive service is selected.
For example, assume that servers for achieving one information retrieval service are located in Tokyo and Osaka when a predetermined information retrieval service needs to be executed from a terminal located in Chiba. In this case, it is preferable that the server located in Tokyo is selected from the point of view of a small network delay. The server located in Osaka, however, may be selected. If the server located in Osaka is selected, convenience is lowered because the terminal located in Chiba receives service of a low quality (large network delay).